​Generaladaptationsyndrome, or GAS, is a termused to describethebody'sshort-termandlong-termreactions tostress.Stressors in humansincludesuchphysicalstressors as starvation, beinghit by a car, or sufferingthroughsevere weather.Additionally,humanscansuffersuchemotional or mentalstressors as theloss of a lovedone,theinability to solve a problem, or evenhaving a difficultday at work.Originallydescribed by HansSelye(1907–1982), an Austrian bornphysicianwhoemigrated to Canada in 1939,the generaladaptationsyndromerepresents a three-stagereaction to stress.Selyeexplainedhischoice of terminology as follows: "I callthissyndromegeneralbecause it is producedonly by agentswhichhave a generaleffectuponlarge portions of thebody. I call it adaptivebecause it stimulatesdefense…. I call it a syndromebecauseitsindividual manifestationsarecoordinatedandevenpartlydependentuponeachother."Selyethoughtthatthegeneraladaptationsyndromeinvolvedtwomajorsystems of thebody,thenervoussystemand theendocrine(orhormonal)system. He thenwent on to outlinewhat he considered as threedistinctivestages in the syndrome'sevolution. He calledthesestagesthealarmreaction(AR),thestage of resistance(SR),andthestage of exhaustion(SE).Stage 1: alarm reaction (ar)Thefirststage of thegeneraladaptationstage,thealarmreaction, is theimmediatereaction to a stressor. In theinitial phase of stress,humansexhibit a "fight or flight"response,whichpreparesthebodyforphysicalactivity.However,this initialresponsecanalsodecreasetheeffectiveness of theimmunesystem,makingpersonsmoresusceptible to illness duringthisphase.Stage 2: stage of resistance (sr)Stage 2 mightalso be namedthestage of adaptation,instead of thestage of resistance.Duringthisphase, if thestress continues,thebodyadapts to thestressors it is exposedto.Changes at manylevelstakeplace in order to reducethe effect of thestressor.Forexample, if thestressor is starvation(possiblydue to anorexia),thepersonmightexperienced a reduceddesireforphysicalactivity to conserveenergy,andtheabsorption of nutrientsfromfoodmight be maximized.Stage 3: stage of exhaustion (se)At thisstage,thestresshascontinuedforsometime.Thebody'sresistance to thestressmaygradually be reduced, or maycollapsequickly.Generally,thismeanstheimmunesystem,andthebody'sability to resistdisease,may be almost totallyeliminated.Patientswhoexperiencelong-termstressmaysuccumb to heartattacks or severeinfectiondue to theirreducedimmunity.Forexample, a personwith a stressfuljobmayexperiencelong-termstressthatmightlead to highbloodpressureand an eventualheart attack.Stress, a useful reaction?ThereadershouldnotethatDr.Selyedidnotregardstress as a purelynegativephenomenon; in fact, he frequently pointedoutthatstress is notonly an inevitablepart of lifebutresultsfromintensejoy or pleasure as well as fear or anxiety. "Stress is notevennecessarilybadforyou; it is alsothespice of life,foranyemotion,anyactivity,."Somelaterresearchershavecoinedtheterm"eustress" or pleasantstress, to reflectthefactthatsuchpositive experiences as a jobpromotion,completing a degree or trainingprogram,marriage,travel,andmanyothersarealso stressful.Selyealsopointedoutthathumanperception of andresponse to stress is highlyindividualized; a job or sportthatone personfindsanxiety-provoking or exhaustingmight be quiteappealingandenjoyable to someoneelse.Looking at one's responses to specificstressorscancontribute to betterunderstanding of one'sparticularphysical,emotional,andmental resourcesandlimits.Causes and symptoms Stress is onecause of generaladaptationsyndrome.Theresults of unrelievedstresscanmanifest as fatigue, irritability,difficultyconcentrating,anddifficultysleeping.Personsmayalsoexperienceothersymptomsthataresigns of stress.Personsexperiencingunusualsymptoms,such as hairloss,withoutanothermedicalexplanationmightconsiderstress as thecause.Thegeneraladaptationsyndrome is alsoinfluenced by suchuniversalhumanvariables as overallhealthandnutritional status,sex,age,ethnic or racialbackground,level of education,socioeconomicstatus(SES),geneticmakeup,etc.Some of thesevariablesarebiologicallybasedanddifficult or impossible to change.Forexample,recentresearch indicatesthatmenandwomenrespondsomewhatdifferently to stress,withwomenbeingmorelikely to usewhat is calledthe"tendandbefriend"responseratherthantheclassical"fight or flight"pattern.Theseresearchersnotethat most of theearlystudies of theeffects of stress on thebodywereconductedwithonlymalesubjects.Selye'sobservationthatpeoplevary in theirperceptions of stressorswasreflected in hisbeliefthatthestressors themselvesarelessdangerous to healththanpeople'smaladaptiveresponses to them. He categorizedcertaindiseases,rangingfromcardiovasculardisorders to inflammatorydiseasesandmentaldisorders as "diseases of adaptation,"regardingthem as "largelydue to errors in ouradaptaiveresponse to stress"ratherthanthedirectresult of suchoutside factors as germs,toxicsubstances,etc.DiagnosisGAS by itself is not an officialdiagnosticcategorybutrather a descriptiveterm. A personwhoconsults a doctorfor aststress-relatedphysicalillnessmay be scheduledforblood or urinetests to measurethelevel of cortisol or otherstress-relatedhormones in theirbody, or imagingstudies to evaluatepossibleabnormalities in theirendocrineglands if the doctorthinksthatthesetestsmayhelp to establish or confirm a diagnosis.TheAmericanPsychiatricAssociation(APA)recognizesstress as a factor in anxiety disorders, particularlypost-traumatic stress disorder(PTSD)andacute stress disorder(ASD).Thesetwodisordersaredefined as symptomatic reactions to extremetraumaticstressors(war,natural or transportationdisasters,criminalassault,abuse, hostage situations,etc.)anddifferchiefly in thetimeframe in whichthesymptomsdevelop.TheAPAalsohas a diagnostic category of adjustment disorders, whicharecharacterizedeither by excessivereactions to stressorswithinthenormal range of experience(e.g.academicexaminations,relationshipbreakups,beingfiredfrom a job) or by significant impairment in theperson'soccupational or socialfunctioning.TreatmentTreatment of stress-relatedillnessestypicallyinvolvesone or morestress reductionstrategies.Stressreduction strategiesgenerallyfallintoone of threecategories:avoidingstressors;changingone'sreaction to thestressor(s); or relievingstressafterthereaction to thestressor(s).Manymainstream as well as complementary or alternative(CAM)strategiesforstressreduction,such as exercising,listening to music,aromatherapy, andmassagerelievestressafter it occurs.Manypsychotherapeuticapproachesattempt to modifythepatient'sreactions to stressors.Theseapproachesoften include an analysis of thepatient'sindividualpatterns of response to stress;forexample,onecommonlyusedset of categoriesdescribespeople as "speedfreaks,""worrywarts,""cliffwalkers,""loners,""basketcases,"and"drifters."Eachpatternhas a recommendedset of skillsthatthepatient is encouraged to workon;forexample,worrywartsare advised to reframetheiranxietiesandthenidentifytheircorevaluesandgoals in order to takeconcreteactionabout theirworries. In general,personswishing to improvetheirmanagement of stressshouldbegin by consulting a medical professionalwithwhomtheyfeelcomfortable to discusswhichoption, or combination of options,theycanuse.Selyehimselfrecommended an approach to stressthat he described as "livingwisely in accordancewithnaturallaws."In hisnow-classicbookTheStress of Life(1956), he discussedthefollowing as importantdimensions of livingwisely:

Adopting an attitude of gratitudetowardliferatherthanseekingrevengeforinjuries or slights.

Actingtowardothersfromaltruisticratherthanself-centeredmotives.

Retaining a capacityforwonderanddelight in thegenuinelygoodandbeautifulthings in life.

Finding a purposeforone'slifeandexpressingone'sindividuality in fulfillingthatpurpose.